Research and development of solar cell modules are being performed. When light is directly incident on a solar cell panel of a solar cell module, that is, when concentration of the light is not performed, the solar cell panel can absorb light from a relatively wide range of angles; but the solar cell panel must have a relatively wide surface area. Therefore, the solar cell module is expensive.
There is a possibility that the cost per surface area of the solar cell module can be reduced by combining the solar cell panel with an inexpensive concentrator. A condensing lens, a concentrator called a CPC (Compound Parabolic Concentrator), etc., may be used as technology for combining the concentrator and the solar cell panel. However, when the condensing lens or the CPC is used in the solar cell module, a drive device becomes necessary to drive the solar cell panel to follow the sun because the orientation of the light of the sun changes according to the season, the time, etc. Therefore, the solar cell module is expensive.
There is a possibility that the cost per surface area of the solar cell module can be reduced by reducing the surface area of the solar cell panel. To reduce the surface area of the solar cell panel, it is desirable to improve the concentration ratio of the solar cell module.